Intracavity stimulated-Raman-scattering transformation of ultrashort light pulses

An investigation is made of intracavity stimulated-Raman-scattering transformation in hydrogen filling an actively mode-locked laser. Reduced equations for the fields of the laser and Stokes waves and equations for the off-diagonal and diagonal elements of the density matrix of the scattering medium are derived. An allowance is made for the influence of the stimulated-Raman-scattering transformation on the generation of the fundamental frequency. A considerable influence is demonstrated of the transient nature of the response of the nonlinear polarization of the scattering medium on the output characteristics of the investigated radiation. Calculations demonstrate a strong reduction in the duration of the Stokes-frequency pulses compared with the duration of the pump pulses.